Is it possible to duplicate a theme and rename it? Eg . 2 x editable copies of Pinterest Inspired theme
Reason being is that i have 2 list pages that will be using the same lauyout theme but each will be customized uniquely.

I have used ‘ Copy to WordPress Theme’ but as soon as i duplicate again with the same layout them it overwrites the previous copy?

Duplicating layout in our plugin is not a good idea. As soon as new update comes, it gets flushed. So what i suggest here is that you can take another layout and copy paste the same code in layout.php and style.php. This way theme name remains different but layout will look alike. Please make sure to use the link Copy To WordPress Theme before making any changes to be safe from updates.